Method and arrangement for determining the water permeability of clothing in a paper machine

ABSTRACT

A method for determining the water permeability of clothing for a machine for producing and/or treating a material web, in particular paper or board web, including the following steps: aiming at least some, in particular high-energy, radiation at the clothing, measuring the amounts of energy penetrating the clothing and/or measuring the amounts of energy reflected by the clothing. In addition, a corresponding arrangement for carrying out the method is specified.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method and an arrangement for determining the water permeability of clothing for a machine for producing and/or treating a material web, in particular a paper or board web.

2. Description of the Related Art

As regards the assessment or measurement of the permeability of clothing and in particular felts, the water permeability is currently used (see, for example, DE 199 17 553 A1, DE 697 10 356 T2, EP 0 024 205 B1, EP 0 383 486 A2, U.S. Pat. No. 4,880,499, U.S. Pat. No. 5,725,737, U.S. Pat. No. 4,892,621, U.S. Pat. No. 5,135,615 and U.S. Pat. No. 5,349,845.

What is needed in the art is an improved method and arrangement for determining the water permeability of clothing.

SUMMARY OF THE INVENTION

The present invention provides further optimization of a method and an arrangement for determining the water permeability of clothing.

The invention comprises, in one form thereof, a further suitable measured variable for determining the permeability of the clothing is also specified, the relevant further measured variable is suitable in particular for assessing the permeability of the clothing with regard to the dewatering behavior in the press nip.

The present invention includes the following method steps:

-   -   aiming at least some, in particular high-energy, radiation at         the clothing, measuring the amounts of energy penetrating the         clothing and/or     -   measuring the amounts of energy reflected by the clothing.

On account of this refinement of the method, the result is a simplification of the measuring apparatus, a non-contact measurement being possible. On account of the lack of interfering variables, the result is more accurate measured values than in the case of contacting measurements. Former disadvantages, such as leakage losses at the nozzle, penetration depths, process-dependent settings and the requirement to adapt the measured variables on account of process changes (papermaking machine speed) are avoided. The clothing can in particular be formed by a press felt.

The energy source which is used to supply the radiation is preferably at least one light source. In this case, in particular a high-intensity light or laser beam can be generated by way of the energy source.

The clothing, and in particular a respective press felt, is increasingly soiled during its running time. The optical permeability has a direct relationship with the soiling and therefore permits a statement about the level of soiling. The level of soiling influences the water absorption and discharge capability of the clothing or of the felt. A relatively high level of soiling would have a negative effect on the amount of water picked up, the elasticity and the compressibility, which, according to the present invention, can now be avoided in a simple and reliable manner.

It is also possible for example to generate a sound wave by way of the energy source that supplies the radiation, an ultrasound wave preferably being generated. In principle, the use of a plurality of energy sources, for example of different types, is also conceivable.

According to a preferred practical refinement of the method according to the present invention, the intensity of the energy source that supplies the radiation is defined as a function of the clothing or felt structure, of the particle sizes of the soiling, in particular fillers, and/or of the web material or paper stock.

The radiation aimed at the clothing can expediently oscillate over the clothing width. In this case, the amount of energy penetrating the clothing can advantageously be measured by of a sensor traversing over the clothing width on the rear side of the clothing, facing away from the energy source. The rate of oscillation is in this case preferably selected to be so high that a measurement is carried out at as many measurement points as possible over the clothing width. It is also advantageous in particular if the energy source that supplies the radiation traverses over the clothing width, and the amount of energy reflected from the clothing is measured and evaluated.

According to a further advantageous refinement of the method according to the present invention, the energy source that supplies the radiation is aimed at the clothing over the entire clothing width, and the amount of energy penetrating the clothing is measured on the side of the clothing opposite the energy source. In this case, the amount of energy penetrating the clothing can be measured on the side of the clothing opposite the energy source in particular by way of a sensor traversing transversely there with respect to the clothing. In specific cases, it can also be advantageous if an energy source that supplies the radiation is in contact with the clothing over the entire side of the clothing.

The energy source that supplies the radiation can in particular also be aimed at the clothing via a transparent medium, preferably glass, in particular opal glass, resting on the clothing. In a corresponding way, configurations are also possible in which the amounts of energy penetrating the clothing or reflected by the latter are measured via a transparent medium, preferably glass, in particular opal glass. Expediently, the radiation aimed at the clothing oscillates between the operator and drive side, in particular at high speed.

The amount of energy penetrating the clothing is preferably measured by way of a sensor traversing on the side of the clothing opposite the energy source. The amount of energy reflected from the clothing can be measured by way of a sensor installed on the side of the energy source. From the measured radiation, conclusions are advantageously drawn about the state of the clothing or felt, in particular the thickness or the soiling.

The advantages of the present invention are achieved by an arrangement or apparatus for determining the water permeability of clothing for a machine for producing and/or treating a material web, in particular a paper or board web, having at least one energy source for aiming at least some, in particular high-energy, radiation at the clothing, at least one sensor for measuring the amount of energy penetrating the clothing and/or at least one sensor for measuring the amount of energy reflected by the clothing.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein:

FIGS. 1 and 2 are a schematic side view and plan view, respectively, of an arrangement for determining the water permeability of clothing, in which radiation produced by an energy source oscillates over the clothing width and the amount of energy penetrating the clothing is measured by a sensor traversing over the clothing width on the rear side facing away from the energy source;

FIGS. 3 and 4 are a schematic side view and plan view, respectively, of an arrangement for determining the water permeability of clothing, in which the radiation originating from an energy source is aimed at the clothing over the entire clothing width and the amount of energy penetrating the clothing is measured on the side of the clothing facing away from the energy source by way of a large number of sensors;

FIGS. 5 and 6 are a schematic side view and plan view, respectively, of an arrangement for determining the water permeability of clothing, in which the radiation originating from an energy source is aimed at the clothing over the entire clothing width and the amount of energy penetrating the clothing is measured on the side of the clothing facing away from the energy source by way of a sensor traversing transversely with respect to the clothing;

FIGS. 7 and 8 are a schematic side view and plan view, respectively, of an arrangement for determining the water permeability of clothing, in which an energy source is in contact with the clothing over the entire clothing width and the amount of energy penetrating the clothing is measured on the side of the clothing facing away from the energy source by way of a sensor traversing transversely with respect to the clothing; and

FIGS. 9 and 10 are a schematic side view and plan view, respectively, of an arrangement for determining the water permeability of clothing, in which radiation produced by an energy source oscillates over the clothing width, the energy source is combined with a sensor which likewise oscillates and is provided on the same side of the clothing for measuring the amount of energy reflected by the clothing, and the amount of energy penetrating the clothing is measured by a sensor traversing over the clothing width on the rear side facing away from the energy source.

Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate one preferred embodiment of the invention, in one form, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings, and more particularly to FIGS. 1 and 2, there is shown in a schematic side view and plan view, an arrangement 10 for determining the water permeability of clothing 12 which, in the present case, is a felt, for example.

In the present case, radiation generated by an energy source 14 oscillates over the entire clothing width. The amount of energy penetrating clothing 12 is measured by a sensor 16 traversing over the entire clothing width on the rear side facing away from energy source 14.

Energy source 14 generates a light beam, for example, which oscillates over the clothing width. By way of sensor 16 traversing over the clothing width, the amount of light penetrating clothing 12 is therefore measured.

FIGS. 3 and 4 show, in a schematic side view and plan view, an arrangement 10 for determining the water permeability of clothing 12, in which the radiation originating from an energy source 14 is aimed at clothing 12 over the entire clothing width. The amount of energy penetrating clothing 12 is measured on the side of clothing 12 facing away from energy source 14 by way of a large number of sensors 16. Clothing 12 can again be a felt, for example.

FIGS. 5 and 6 show, in a schematic side view and plan view, an arrangement 10 for determining the water permeability of clothing 12, in which the radiation originating from an energy source 14 is aimed at clothing 12 over the entire clothing width and the amount of energy penetrating clothing 12 is measured on the side of the clothing facing away from energy source 14 by way of a sensor 16 traversing transversely with respect to clothing 12. Clothing 12 is again formed by a felt, for example.

In the arrangement 10 reproduced in FIGS. 7 and 8, an energy source 14 is in contact with clothing 12 over the entire clothing width. In this case, energy source 14 that supplies the radiation can be aimed at clothing 12 in particular via an opal glass 18 resting on clothing 12. The amount of energy penetrating clothing 12 is measured on the side of clothing 12 facing away from energy source 14 by way of a sensor 16 traversing transversely with respect to clothing 12. Clothing 12 is again a felt, for example.

FIGS. 9 and 10 again show, in a schematic side view and plan view, an arrangement 10 for determining the water permeability of clothing 12, in which radiation produced by an energy source 14 oscillates over the clothing width. In this case, energy source 14 is combined in the present case with a sensor 20, which likewise oscillates and is provided on the same side of clothing 12, for measuring the amount of energy reflected by clothing 12.

The amount of energy penetrating clothing 12 is measured by a sensor 16 traversing over the clothing width on the rear side facing away from energy source 14. For this purpose, this sensor 16 is assigned an appropriate traversing unit 22. Clothing 12, which again can be a felt, for example, is led around a deflection roll 24. As can be seen from FIGS. 9 and 10, the measurement of the water permeability is carried out in the vicinity of deflection roll 24.

While this invention has been described as having a preferred design, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.

List of Designations

-   -   10 Arrangement, apparatus     -   12 Clothing, felt     -   14 Energy source     -   16 Sensor     -   18 Opal glass     -   20 Sensor     -   22 Traversing unit     -   24 Deflection roll 

1. A method for determining a water permeability of a clothing for a machine for at least one of producing and treating a material web, comprising the steps of: aiming a radiation energy at the clothing; and measuring at least one of an amount of said radiation energy penetrating the clothing and an amount of said radiation energy reflected by the clothing.
 2. The method of claim 1, wherein the material web is one of a paper web and a board web.
 3. The method of claim 1, wherein said radiation energy is a high energy radiation.
 4. The method of claim 1, further including the step of forming the clothing by a press felt.
 5. The method of claim 1, further including the step of supplying said radiation energy with an energy source, said energy source being at least one light source.
 6. The method of claim 5, further including the step of generating at least one of a high intensity light and a laser beam with said energy source.
 7. The method of claim 1, further including the steps of supplying said radiation energy with an energy source and generating a sound wave with said energy source.
 8. The method of claim 7, wherein said energy source generates an ultrasound wave.
 9. The method of claim 1, further including the steps of supplying said radiation energy with an energy source and defining an intensity of said energy source as a function of at least one of a clothing structure, a felt structure, a plurality of particle sizes of a soiling, a plurality of fillers of said soiling, the web material and a paper stock.
 10. The method of claim 1, further including the step of oscillating said radiation energy over a width of the clothing.
 11. The method of claim 10, further including the steps of supplying said radiation energy with an energy source and measuring said amount of said radiation energy penetrating the clothing by a sensor traversing over said width of the clothing on a rear side of the clothing, said rear side facing away from the energy source.
 12. The method of claim 10, wherein said radiation energy includes a rate of oscillation which is selected so that so that said measuring step is carried out at as many measurement points as possible over said width of the clothing.
 13. The method of claim 1 further including the steps of supplying said radiation energy with an energy source, traversing said energy source over a width of the clothing, measuring said amount of said radiation energy reflected by the clothing and evaluating said amount of said radiation energy reflected by the clothing.
 14. The method of claim 1, further including the steps of supplying said radiation energy with an energy source, aiming said energy source at the clothing over an entire width of the clothing and measuring said amount of said radiation energy penetrating the clothing on a side of the clothing opposite said energy source.
 15. The method of claim 14, further including the steps of measuring said amount of said radiation energy penetrating the clothing on a side of the clothing opposite said energy source by a sensor and traversing the clothing transversely with said sensor.
 16. The method of claim 1, further including the steps of supplying said radiation energy with an energy source and contacting the clothing with said energy source over an entire width of the clothing.
 17. The method of claim 1, further including the steps of supplying said radiation energy with an energy source and aiming said energy source at the clothing via a transparent medium resting on the clothing.
 18. The method of claim 17, wherein said transparent medium is a glass.
 19. The method of claim 17, wherein said transparent medium is an opal glass.
 20. The method of claim 17, wherein at least one of said amount of said radiation energy penetrating the clothing and said amount of said radiation energy reflected by the clothing are measured via a transparent medium.
 21. The method of claim 20, wherein said transparent medium is a glass.
 22. The method of claim 20, wherein said transparent medium is an opal glass.
 23. The method of claim 1, further including the step of oscillating said radiation energy between an operator side of the machine and a drive side of the machine.
 24. The method of claim 23, said radiation energy oscillates at a high speed.
 25. The method of claim 23, further including the step measuring said amount of said radiation energy penetrating the clothing with a sensor traversing on a side of the clothing opposite said energy source.
 26. The method of claim 23, further including the steps of supplying said radiation energy with an energy source and measuring said amount of said radiation energy reflected from the clothing by a sensor installed on a side of the clothing of said energy source.
 27. The method of claim 1, further including the step of drawing conclusions from said measuring step about at least one of a state of one of the clothing and a felt, a thickness of one of the clothing and a felt and a soiling of one of the clothing and a felt. 